Harvard-affiliate McLean Hospital loses patient data by Barb Darrow @FortuneMagazine July 29, 2015, 12:24 PM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons This is bad but could get worse: McLean Hospital, a member of the Boston-area Partners Healthcare colossus and Harvard Medical School affiliate, has lost track of four backup tapes full of personal information on brain research subjects. According to The Boston Globe, the unencrypted tapes from McLean’s Harvard Brain Tissue Resource Center went missing on May 29. They contain names, birth dates, diagnoses, and some social security numbers of 12,600 people who had donated their brains for research, as well as some information on their family members. Most, but not all, of the subjects are deceased. In a statement, a spokesperson for the Belmont, Mass.-based psychiatric hospital told the Globe that while the tapes are indeed missing, there is “no reason to believe that any of the information … has been accessed or used inappropriately.” Getting at the information would require special software and technical expertise, according to the hospital. Even if the tapes are recovered without harm, this snafu raises questions, chief among them why isn’t all patient data encrypted? This isn’t Partners Heathcare’s first brush with data security concerns: In May, some 3,300 patients were hit by a phishing attack seeking to get their information. Sign up for Data Sheet, Fortune’s daily newsletter about the business of technology.